Phase modification



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H. A. ROWLAND. PHASE MODIFICATION.

No. 547,683. Patented Oct. 8

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H. A. ROWLAND. PHASE MODIFICATION.

No. 547.683. Patented Oct. 8, 1895.

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Patented Oct 8, 1895.

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H. A. ROWLAND.

PHASE MODIFICATION.

'No. 547,683. Patented 001:. 891895.

wwwwoeo (NoModeL) 9 Sheets-Sheet 9. H. A. ROWLAND.

PHASE MODIFICATION.

Patented Octlj8, 1895.

PATENT OFFICE.

HENRY A. ROWLAND; )F BALTIMORE, MARYLAND] PHASE. MODIFICATION.

SPECIFICATION forming part of Letters Patent No. 547,683, dated October8, 1895.

Application filed May 19,1894. Serial No.

611,251. (110 model.) Patented in England June 7,18%,170. 11,059, and inPraline June 7, 1894, No. 239,124.

To all whom it may concern:

Be it known that I, HENRY A. ROWLAND, a citizen of the United States,residing at Baltimore, in the State of Maryland, have invented certainnew and useful Improvements in Methods of Varying the Frequency andNumber of Phases in a Polyphase Current, (for which I have obtainedLetters Patent in Great Britain, No. 11,059, dated June 7, 189i, and inFrance, No; 239,124, dated June 7, 18%;) and 1 do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same. 1

My invention relates to methods of varying the frequency and number ofphases in a polyphase current; and the object of this invention is tovary the frequency of a polyphase current from zero to any desiredfrequency, as may be desired, to produce means forstarting synchronousand other motors and causing them to run at different speeds and toaccomplish with other translating devices a variety of other results ofa like nature. To accomplish this I use the combination, with acommutator which may be either stationary or revolving,'ot brushes whichmay be either revolving or stationary. The bars of the commutator arejoined toconductors from the source of electricity either directly or bymeans of contact rings and brushes, and the current is carried from thecommutator by brushes rubbing thereon, these latter brushes beingeitherfixed or revolving independently of the commutator, as will behereinafter described; or the current may enter the brushes and becarried off from the commutator-bars, if desired. Currents from thesebrushes'or commutator-bars may be taken directly from -them when theyare stationary, or through contact-rings and other brushes whenrevolving.

Reference is had to the accompanying drawings, in which the same partsare indicated by the same letters throughout the several views.

Figure 1 represents a perspective view of a commutator and brushesmounted on independent shatts and capable of revolving independently ofeach other. Fig. 2 represents a modification of the same device in whichthebrushesonlyrevolve,theconductorsbeing I joined directlyfi'o'the barsof the commutator, which is fixed. Fig. 3 represents afurthermodiiication of the device shown in Fig. 1, with the conductorsjointed directly to the brushes, which are fixed, while the commutatoris adapted to revolve. Fig. 4. represents a revolving commutator andfixed-brushes, the conductors leading directly from the brushes to thecontact-brushes of a motor or dynamo. Fig. 5 differs from Fig. 4 inhaving the commutator stationary and the brushes revolving. Fig.5showsalead of the conductors somewhat different from the constructionshown in Fig. at. Fig. 7 shows a lead of the conductors somewhatdifferent from the construction shown'in Fig. 5. Fig. 8 is a similarview to that shown in Fig. 1, and showsa method of preventing therevolving brushes from leaving the commutator-surface under the actionof centrifugal force; Fig. 9 represents an end view of the revolvingbrushes shown in Fig. 8. Fig. 9 represents an end view of another devicefor adjusting the revolving brushes against the action of centrifugalforce. Fig. 10 shows in section a means of gearing together the shaftcarrying the commutator and the one carrying the brushes, so that theywill maintain a fixed ratio in theirv speeds. Fig. 10 represents asection along the line x a:

of Fig. 9. Fig. 11 represents a section along the line 11 11 of Fig. 10,and looking in the direction of the arrow. Fig. 12 represents adiagrammatic view of the revolving commutator and brushes shownin Fig.1, with conductors leading from the side of the revolving brushes to thecontact-brushes of a motor or dynamo. Fig. 13 represents the revolvingbrushes shown in Fig. 1 mounted to revolve .on the'commutator of adynamo or motor. Fig,

UNITED ST TES- PATENT OFFICE.

HENRY A. ROWLAND, (5F BALTIMORE, MARYLAND.

PHASE MODIFICATION.

SPECIFICATION forming part of Letters Patent No. 547,683, dated October8, 1 895. f

Application filed May 19,1894. Serial No. 51l,851. (N model.) Patentedin England June 7,1894, No. 1;;059, an gin France June '7, 1894.110.239,124.

I as

To all whom it may concern: I dependently ofeach other.

Be it known that l, HENRY A. ROWLAND, a modification of the sam 4 ig.ggiepresents devi'e in which a citizen of the United States, residing atthebrushesonlyrevolve,t conductors being Baltimore, in the State ofMaryland, have injoined directly/to the bars 'f commutator, 5 ventedcertainnew and useful Improvements which is fixed. Fig. 3 presents afurther in Methods of Varying the Frequency and modification of thedevce I iovvn in Fig. 1, Number of Phases in a Polyphase Current, withthe conductors jo (for which I have obtained Letters Patent in brushes,which are fi. lreat Britain, No. 11,059, dated June 7, 1894., tator isadapted to rev L0 and in France, No." 239,124, dated June 7, a revolvingcommutr and fixed brushes, 1894;) and 1 do hereby declare the followingthe conductors lea g directly. from the to be afull,clear, and exactdescription of the brushes to the conta f 'brushes of a motor orinvention, such as will enable others skilled dynamo. Fig. 5 dirs fromFig. 4 in having in the art to which it appertains to make and thecommutator st ionary and the brushes use the same. revolving. Fig-6owsalead of the conduc- My invention relates to methods of varying torssomewhat ditt nt from the construction .ig. 7 shows a lead of thethetrequency and number of phases in a polyshown in Fig.

phase current; and the object of this invenconductors someiiv atdifferent from the co'ntion is to vary the frequency of a polyphasestruction show li Fig. 5. Fig.8 is a similar 20 current from zero to anydesired frequency, view to that ,Eho ,n in Fig. 1, and shows a 10 as maybe desired, to produce means forstartmethod of pg leve ing the revolvingbrushes ing synchronous and other motors and causfrom leavingftheommutator-surface under ing them to run at different speeds and to theactiong cei 'rifngal force; Fig. 9 rep- Fig. 4 representsaccomplish withother translating devices a resents an fnd v of the revolving brushes 25variety of other results of a like nature. To shown in it; g. 8. lg. 9represents an end view accomplish this I use the combination, with a ofa-nothf devi for adjusting the revolving commutator which may be eitherstationary brushes gainst eaction of centrifugal force.

' or revolving,'ot brushes which may be either Fig. 10 (hows i section ameans of gearing l revolving or stationary. The bars of the comtogeththe sh it carrying, the commutator I 0 mutator are joined to conductorsfrom the and me one car: ling the brushes, so that they ffixed ratio intheir speeds.

ts a section along the line-a: a:

source of electricity either directly or by will aintain means ofcontact rings and brushes, and the Fig. represe current is carried fromthe commutator by of F g. 9. Fl :11 represents a section along brushesrubbing thereon,these latt'erbrushes the inc ll 11 o Fig. 10, andlooking in the 35 being either'fixed or revolving independentlydigp'ction of thfarrow. Fig. 12 represents a of the commutator, as willbe hereinafter decli grammatic iew of the revolving coinmuscribed; orthe current may enter the brushes t "or and brus es shown 'in Fig. 1,with conand be carried off from the commutator-bars, d ctors leadinifromthe side of the revolving if desired. Currents from these brushes or'ushes to the ontact-brushes of a motor 01' o commutator-bars may betaken directly from vnamo. Fig 13 represents the revolving o -them whenthey are stationary, or through brushes show} in Fig. 1 mounted torevolve contact-rings and other brushes when revolvyou thecommu itorofadynamo or motor. Fig. ing. I it shows the I thod of indicatinggraphically Reference ishad to the accompanying draw- 4 the intensityQnd phase of an electromo-tive 5 ings, in which the same parts areindicated; force. Fig. l shows the method of finding by the same lettersthroughout the several I the intensity views.

n phase of an electromotive force, which the resultant of two electro-Figure 1 represents a perspective view of a commutator and brushesmounted on indemotive forcefiot dilierent phases acting in 5o pcndentshafts and capable of revolving inseries. Fig. '6 shows the graphicmethod of determining ratio of the windings in the re ent angularvelocities, it will be understood that a commutator-bar is theequivalent of-a flowin g f rom the conductors K K the brushes F FIferent frequency than This frequencywill depend on the original versa.

brush, and vice the shaft of a motor or other EL represents "translatingdevice.

L'-;(shown in Fig. 21) represents a synchronous or induction motor.

L (shown in dynamofor other translating device having fixed brushes L inaddition to the revolving brushes F. I r I Fig. 10 shows a methodofgearing the shaft .Gg which carries thebrushes F to the shaft B, whichcarries the commutator A. The shaft G is hollow, allowing the shaft B topass through it. On the end. of shaft B is a cogwheel B, meshing with thcog-wheel N, which turns on the pin 42, secured to the rigid arm M. ThewheelN meshes with the cog-wheel.

53', which is rigidly securedto the shaft G, thus causing the shaft Gtorevolve in a fixed ratio tothe shaft B. It is'obvious that a variablespeed-gear or any other suitable gearing for connecting the two shaftsmay be adopted,

if'desired. p 'Q, R S T are the conductorspf a two-phase system.

U and U in Figs. 17, 21, and 22. and also U in Fig-20 are the primarycoils of the transformers.

\Vh'en the apparatus is at rest, the current will be identical in allrespects to that entering at E E, provided the number of brushes, rings,and bars is the same throughout. If the commutator A is driven'by asynchronous motor the brushes F remaining at rest, any-pair of thesebrushes will yield a continuous current, which can be taken off directlyfrom the brushes or from the corresponding conductors K." If the brushesF are now driven by a synchronous motor they will assume a fixedposition relative to the commutator A, and the current passing out at KK will be identical in every respect to that entering at E E. It isevident from the above that in passing from a current of zero frequencyto one equal in frequency to that entering at E the intermediate stageshaverbeen passed corresponding to the difierent speeds of the brushes FF. Therefore if are driven at any other speed than that of synchronismthe current passing through the conductors K K will have a difthatentering at E E.

combined with the difference in frequency From this it followsspeedof'the two parts.

' that it is entirely immaterial whether the commutator alonerevolves,or whether the brushes alone revolve, or whether both revolve,so long as the difference in speed of the two parts is the same. If apart of the brushes F B only are used, the number of phases of thecurrent flowing through the corresponding conductors K K will beproportionally reduced. The number of commutator-bars and conductors Ecan be different from the brushes and conductors K.

Figs. 13 and 22). represents a '3, GOHtlllllOllS current dlld.

Such a commutator will transform any polyphase current into any other,the'number of phases being in proportion to the number of conductors Eand K and the digference of the frequencies being determined y therelative rates of revolution of the brushes and commutators.

This device may be utilized in a variety of Ways.

E irst. To make a dynamo capable of giving out currents of anyfrequency, mount the device on the shaft of the dynamo, as shown in Fig.13 or indicated in Fig. 2. The commutator may now become the commutatorof the dynamo, and the armature-conductors may be conducted directly tothe bars of the commutator. On now revolving the brushes a polyphasecurrent of any frequency can be obtained from the brushes I. The brushescan be driven from the shaft'at any desired speed by gearing or belts orpendently driven by a motor. 1? in Fig. 13 represents a pulley fordriving the shaft G.

Second. This samedevice (shown-in Fig. 13) makes a motor capable ofstarting and running in a variety of ways. (a) It is a self-startingsynchronous motor provided the brushes are revolved at the proper speedand afterward clamped to belts, gearing, 850., so as to preserve thefixed ratio of speed. -(b.) When the brushes are run by asniallsynchronous motor and fthey are fed by a poly phase current the motorwill then be fed by will start, run,'and stop like such acontinuous-current motor. (0.) When running in either of these wayscontinuous current can be taken off by a pair of fixed brushes and usedfor exciting the field-v magnets or any other purpose. ((1.) The devicementioned in section (a) can be used to convertcontinuous into apolyphase alternating current of any number of phases and any frequency.

Third. If used to start or to vary the speed of an induction orsynchronous motor, Figs. 4,, 5, 6, 7, 12, and 22 show the connectionsfor the various methods of using this device. The brushes F may be atrest, as it is onlynecessary to revolve one part. The connections to themotor and to the source of current may be made from either side of thedevice. By this arrangement current can be supplied to the motor at' anydesired frequency, and it will be self-startin g. By regulating thespeed of the moving part by belt, gearing, or other devices thefrequency of the currentreaching the motor can be controlled, andconsequently its speed which will be in synchronism with the currentreaching it. The speed of the moving part may be decreased as the motorspeed increases, and when broughtto rest the motor will reachsynchronism with the original current. If the commutator be made the maybe indecommutator of a motor and a polyphase currentbe supplied throughthe brushes F F,

Fi s. 2 and 13, thenthe frequency of the cur- 'rent reaching thearmature and the consequent speed of the armature can be varied byvarying the speed of the brushes.

Fourth. To start a motor under a load, Figs. 4, 5, 6, 7, 13, and 21 and22: By driving the brushes by asynchronous motor the large motor willstart under a load and run at a speed depending on the electromotiveforce.

Fifth. To start a synchronous motor under a load: Applied as above asynchronous motor field may obviously be interchanged.

The source of polyphase currents may bea generator or a transformer ortransformers. Moreover, the transformers may be so constructed that apolyphase current of one system is converted into a polyphase current ofanother system-such, for instance, as are described in my application,Serial No.517,726, filed July 16, 1894:. In Fig. the connections aremade by connecting similar letters and using a b 0 cl, &c., to take offthe polyphase current.

In 14 the length of OZ represents the amount of an electromotive force,and its phase is represented by the angle cc, the zero of phlase beingOX. Hence any given line'in the diagrams represents the amount and phaseof the electromotive force along any wire, as is Well known to thoseskilled in the art. If we have an electromotive force along a given wireand join to it another electromotive force of the same frequency, but adifferent phase, the resultant electromotive force is given by a c, theoriginal pa'rts of theforce being at a c in Fig. 15, and its phase bythedirection of b and a cl. Thus in Fig. 17 I wind the coil a 2' and layoff its electromotive force a i in Fig. 16 proportional to the numberofcoils in a 2'. Similarly i b is laid off at right angles to a i becausethe coil is wound on the second transformer having a phase ninetydegrees from the first. Thus the whole. system. of electromotive forces,as shown, is equivalent to the system 0 a, 0 Z), 0 c, 0 d, 0 e, of, 0 g,0 7a, which, being all equal and at equal angles, make an open poiyphasesystem of eight phases. Joining a b, b c, &c., the lines will representthe electromotive forces and phases in a polyphase system of theclosed-circuit variety. In general any system of electromotive forcescan be constructed out of two or more original ones. lVhen the polyphasesystem is not symmetrical, the figure a b c d e f g it will not besymmetrical. To construct a diagram in general, lay down on paper anynumber of points a b c, &c., and

connect them together by lines drawn parallel to the given electromotiveforces. Then wind the coilsproportional'to these lines.

In transformers for a poly-phase system electromotive forces indifferent phases are induced and the intensity depends on the ratio ofthe primary and secondary windings. Hence any polyphase current can beobtained from any two transformers whose phases differ in any degreefrom each other.

Figs. 16 and 17 represent an eight-phase system of electromotive forcesderived from a pairof transformers of the two-phase system. The twotransformers are each wound with six secondary coils, the windings oftwo coils being proportional to a i and of four coils proportional to tb. The coils shown in Fig. 17 are connected, as shown in Fig. 16-thatis, the number of coils in the segment a i of the secondary winding isproportional to the length of the line a 'II in Fig. 16, and so on forthe other segments, the wires leading from eight points a b c d efg hforming the conductors of the eight-phase system. The con 'ductors Q R ST represent the conductors of the two-phase system and U and U theprimary coils of the transformers.

In Fig. 18 an open-circuit system is shown,

the arrangement of the wires in the secondary coils being similar tothat indicated by the single pair of coils a '11 and i b in opencircuit, as shown. On each transformer there will then be in this casefour large and four small coils, two of which are connected, as shown inFig. 18, the rest being omitted for the sake of clearness in thedrawings.

Fig. 19 represents the method of connecting the secondary coils and therelations of the windings to produce a twelve-phase system. In this caseone set of coils is proportional to a m and the other set to m b.

Fig. 20 shows the arrangement of the coils for a twelve-phase systemderived from a three-phase. The connections are made by connectingsimilar letters and using wires 0!. b c d, &c., to take off thepolyp'hase current; Two of these connections are shown at (Z and e inFig. 20, the rest being omitted for the sake of clearnes's in thedrawings.

Fig. 21 shows the combination of an eightphase system derived from atwo-phase, as in Fig. 17, with the device for varying the frequencyshown in Fig. 1, and a synchronousmotor operated thereby. It the brushesF remain fixed and the commutatorA is revolved by a synchronousmotoracontinuous current is produced in the conductors K. If not runsynchronously an alternating current is pro duced. a synchronous motor,the brushes F are revolved, an alternating current is produced whosefrequency depends on the original frequency and on the difference inspeed between the brushes F andthe commutator A. Any other translatingdevice may be substituted for the synchronous motor shown in thisfigure. The conductors from the transformers "may also'be connected tothe brushes I, and a motor may be mounted on the shaft B, as showninFig. 22, in which the brushes If, when the commutator A is run by" Fare made to revolve on the commutator A of the motor L If revolvedsynchronously, a continuous current will be supplied to the motor; butat any other speed an alternating current will be supplied, and henceeither a continuous-current motor or an alternatingcurrent motor may beused at L In'the diagram shown in Fig. 23 the closedcircuit transformerof Fig. 17 is connected to one of the combinations of armature andbrushes shown in Figs. t to 7, while the opencircuit transformer shownin Fig. 18 may be similarly connected, if desired. The transformer isrepresented as connected to the upper device on the sheet, and thedotted lines indicate that it may be connected to any one or more of theother. devices. It will be seen that a continuous current will becarried off by the pairs of conductors to the right of the said diagram,provided these devices are run in synchronism with the current, while analternating current will be carried off at any other relative speed, thepolyphase current from the transformer being converted into a continuouscurrent or an alternating by means of the commutator A and brushes F orF, either or both of which may be made to revolve. It is evident thatthe speed of the commutator necessary to produce continuous currents canbe reduced one-half, one-third, &c., by making the number of thecommutator-bars two, three, dire, times the number of wires from thetransformer.

In the specification and claims a continuous current is considered to bean alternating current of zero frequency. It will thus be seen that byan arrangement similar to that herein shown it is possible to transforman alternating current of any number of phases and frequency to analternating current of any desired number of phases and frequency, andto further change this latter current either into a continuous currentor an alternating current of greater or less number of phases andfrequency, to run a synchronous or induction motor thereby at anydesired speed, to start the same under a load, and to accomplish thegreat variety of results hereinbefore described, as well as many othersthat would readily suggest themselves to any skilled electrician.

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States, is-

1. The combination with a source of alternating currents of electricityof a commutator or'brushes, a plurality of electrical conductorsconnecting said source of electricity with said commutator or brushes, apluralityof brushes or commutator bars adapted to take otf the current,means for varying the angular velocity of said commutator bars relativeto said brushes, and a synchronous electric motor, distinct from saidcommutator, and said brushes electrically connected either to saidbrushes or to said commutator bars, and re- 2. The combination with asource of alternating currents ofelectricity, of acommutator and aplurality of electrical conductors connecting said source of electricitywith said commutator, of a plurality of brushes adapted to take thecurrent from said commutator, means for revolving said commutator andsaid brushes independently of each other, and a synchronous electricmotor, distinct from said commutator and said brushes connected to saidbrushes and receiving currents therefrom, substantially as described.

3. The combination with a source of alter nating currents of electricityof aplurality of electrical conductors connecting saidsour'ce ofelectricity with said commutator, a plurality of brushes adapted to takethe current from said commutator, means for varying the angular velocityof said commutator relative to said brushes, and a synchronous electricmotor, distinct from said commutator and said brushes, and electricallyconnected to said brushes and receiving currents therefrom,substantially as described. l

4. The combination with a source of polyphase currents of a plurality oftransformers so connected thereto that some of the secondary currentspass through windings on aplurality of the transformers, thus producinga polyphase current of a-different number of phases from the primarycurrent, a commu tator or brushes, and a plurality of electricalconductors connecting said transformer with said commutator or brushes,of a plurality of ibrushes or commutator bars adapted to take {off thecurrent, means for producing a relati"verotation between said commutatorand said brushes, and a translating device electrically connected tosaid brushes or to said commutatorbars, substantially as described.

5. The combination with a source of polyphase currents, of a pluralityof transformers so connected thereto that some of either the primarycurrents or the secondary currents pass through windings on a pluralityof the transformers, thus producinga polyphase current of a difierentnumber of phases from the primary current, a commutator or brushes, anda plurality of electrical conductors connecting said transformer withsaid commutator or brushes, a plurality of brushes or commutator barsadapted to take 0d the current, means for varying the angular velocityof said commutator relative to said brushes,

nected to said brushes or to said commutator bars, substantially asdescribed. 6. The combination with a source of polyphase currents, of aplurality of transformers so connected thereto that some of the secondary currents'pass through windings on two or more .of the transformers,thus producing a polyphase current of a different number of ceivingcurrents therefrom, substantially as described.

and a translating device electrically conphases from the primarycurrent, a commutator or brushes, a plurality of electrical conductorsconnecting said transformer with said commutator or brushes, and meansfor drivpass through windings on two. or more of the 'j transformers,thus producing apolyphase curr ent of a difierent number of phases fromthe 7 primary current, a commutatingdevice, a plu- 'ralit'y ofelectrical conductors connecting sald transformer with said cornmutatingdevice and means for driving the coinm utating device in synchronismwith the current, or at g any integral multiple of saidspeed for the Ipurpose of converting the polyphase current no, into acontinnouscurrent, and means for car- .uyingofi said con tially as described.

8. The method of starting a synchronousmotor which consists in producinga continu-. ,,.g5 ous current from an alternating one by means of acommutating device in synchronisin with .the current andgradually-increasing the frequency of the current, by slowing down thecommutating device until it COIIIQSIO rest, substantially as described;

tinuous current, substans 9. The combination with a disk slotted in anapproximately radial direction, of a brush holder adapted to slide insaid slot and provided withfa rack on one side thereof, of a slidingweight having a gnidelug projecting into another one of said slots, andalso pro-' vided with rack-teethon one side thereof, and

a gear wheel pivotally mounted on said disk between said sliding weightand said brush holder and meshing in the rack-teeth on each,substantially as described.

.10. The combination with a disk slotted in an approximately radialdirection, of a brush holder adapted to slide in said slot and providedwith a rack on one side thereof, and a spripg adapted to press saidbrush holder toward the center of said disk, of a sliding weight havinga guide lug projecting into another one of said slots, and also providedwith rack teeth on one side thereof, and a gear wheel pivotally inountedon said disk between said sliding weight and said brush holder andmeshing in the rack teeth on each, substantially as described. a

1 In testimony whereof I affix my signature in presence of twowitnesses.

. HENRY A. ROWLAND.

Witnesses:

' JOSEPH S. AMES,

WILLIAMB. CLARK.

